Firstly, you're not using your back for power. Punching is always about torguing the body. This means you're not twisting those hips, that upper body and most of all your feets are planted like a tree in the ground.

Mostly arm punches...

Secondly, you keep dropping your hands every now and then. I see what you were doing there... To fake a punch, you need to telegraph it! Bend those knees, lean forward with the lead hand, extend the arm but bend the elbows so your hand goes down.

A good fake is one that let's you economically set you up for another strike i.e. fake a lead to a cross.

Thirdly, keep hands up?

Fourthly, You're not stepping in with the punches. You're just not generating enough power by standing still. When you jab, you need to step in. When you punch, you step in. Period.

Fifth and last, if you're going to punch to the lower upper body, you need to drop level to punch. Only punch at eye level. If you're going to punch the chest, you're going to need to bend your knees so you drop a level down, then push with the rear leg and deliver the punch.

My advice;Get the instruction from a qualified instructor before proceeding. You may just injure your hands if you keep doing this.

Who said boxing's easy?

-Donnie out

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I got two fists.. Don't make me use my head as well!

not bad mate,i'd just say work on getting maximum range with your jab and twist a bit more with the back hand also think of literally breaking it as you hit it rather than pushing/punching behind the bag.

also you as has been said you were dropping your hands as the punches came back (while you were still in range)

it was a little bit frenzied; get in range get your combo off get out of range then steady the bag,

Keep hands up when you get deep into a combination. a hook will be a nasty surprise if you keep dropping your hands. Maybe plant your feet for more power as well. Try adding in avoidance with your combinations. AKA imagine slipping a punch, then counter it with a body hook.

Everytime you cross punch you stick your head forward. If your opponent notices they will just sway your cross and nail you with a hook. Also watch your double punching (when you have both arms extended at the same time. don't do another punch until your first punch has come back to your head

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Pain is weakness leaving the bodyThe more you sweat in the gym the less you bleed in battle

Not bad. Try to attack the cnterline. The imaginary line that travels vertically through the center of your opponent. This is always the best option when available. Also try to even your weight. You looked heavy on the front leg.

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"When I let Go of who I am, I become who I might be." Lao Tzu

Looks like your energy is good.A few points to ponder;1)You are a counterpunchers dream opponent with the way you leave your head unprotected.2)Not many hooks to the head. Might want to work some in there.3)The constant swinging of the bag tells me that you are push-punching instead of snapping your punches.A proper snapping punch will cause the heavybag to shake rather than swing wildly.Push-punching will tire you quickly in a real match, and if you miss with a push-punch, you'll be off balance and wide open for a counter.Practice throwing more punches from shoulder level, then comong back to guard quickly. Also practice snapping your punches. It'll feel weird at first because you'll have to use less power until you get the hang of it, but when you do, you'll be able to punch harder and throw faster combos without getting as winded.